Differential gearing



May 20, 1941. J. E. cAsNl-:R

DIFFERENTIAL GEARING 2 Sheets-Sheet 1 [Iii Il Original Filed Sept. 25, 1939 n., 3 v EW JAMES E. CASNER May 20, 1941- J. E. cAsNER l 2,242,605

DIFFERENT IAL GEAR ING original Filed sept. 2s, i939 2 sheets-sheet 2,

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- JAMES E.CASNER Patented May 20, 1941 ATENT OFFICE 2,242,605 niiirsanNTIAL GEARING .lames E. Casner, Alpine, Tex.

2 Claims. (Cl. i4-310) This invention deals with an improved form of differential gearing for automotive vehicles and relates, more particularly, to a structure of this character wherein the dierential gearing associated with the driving wheels of the vehicle are located on the power shaft of the vehicle rather than on the axles for said wheels.

While the differential gearing of the present invention is one of general utility and adapted for various installations, it is particularly suited for use with vehicles of the type having a chassis embodying independent Wheel suspension units together with individual driving means associated with the driving wheels of the vehicle.v Such an automobile chassis construction is disclosed in prior copending application Serial Number 296,- 484, led September 25, 1939, and of which the present application is a division.

A primary object of the present invention is to provide a simple, compact and reliable differential gearing mechanism which is located on the power shaft of the motor vehicle in a manner whereby power from the motor is transmitted equally and uniformly to auxiliary drive shafts connected to the driving wheels of the vehicle.

Another principal purpose of the invention is for the provision of a diiierential gearing of this character which is adapted to rotate the drive shafts in opposite directions such that the torque of one equalizes that of the other in a manner to eliminate a primary cause for objectionable swaying of the vehicle body at high speeds and otherwise make possible even and uniform riding qualities at all times in contrast to vehicles having only a single drive shaft which, of course, develops an unbalanced torque at high speeds and results in dangerous swaying of the Vehicle body and difficult control of the vehicle.

Further objects and advantages, and other new and useful features in the construction, arrangement and general combination of parts of the invention will be apparent as a description thereof proceeds with reference to the accompanying drawings in which like reference characters designate like parts throughout, and in which:

Fig. 1 is a horizontal sectional view through a differential casing illustrating in plan the improved dilferential gearing of the present invention, parts thereof being shown in section;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1, locking in the direction ofthe arrows; and,

Fig. 3 is a plan view of the chassis of a motor vehicle showing the general organization thereof including the wheel driving mechanism and illustrating the relation therein of the improved differential gearing of the present invention.

Referring now, more particularly, to the drawy ings, the numeral I, Fig. 3, designates generally the longitudinal side beams or rails which together with cross members 3, il, form the frame for supporting the body of the automobile or other vehicle. Substantially centrally between the ends of the frame is a transversely disposed horizontal main shaft by Which the independent front wheel suspension units 6, 'I and substantially similar rear wheel suspension units 8, 9 are i mounted in the general chassis organization.

A forwardly mounted motor M including the transmission designated generally T, is carried ,at one end by the forward cross frame member 3 and at its opposite end by a suitable support comprising a sleeve I0, or the like, attached t0 said horizontal main shaft 5. The differential mechanism D is contained within a casing Il, disposed slightly rearwardly of said main shaft 5 in close proximity to the transverse median of the chassis and is preferably of a type which is built in with the transmission together with a suitable partition to divide the volume of grease.

A pair of stub shafts I2, I3, extend from the differential casing II to universal couplings I4, Ill connected to a pair of opposite outwardly inclined drive shafts I5, I5 which lead into gear cases I 5, I6 containing a part of the gearing for driving the rear Wheels Il of the vehicle, the front wheels thereof being designated generally I8.

The transverse main shaft 5 is journalled at either end to a pair of substantially triangular hanger. units 2li having bearing openings in generally triangularly spaced relation for supporting auxiliary horizontal shafts 23, 24, and otherwise provided with means for mounting the vehicle frame member I over the running gear.

The mounting of the vehicle wheels is provided, as stated, by individual suspension units 6, 1, for the front wheels I8, and 8, 9, for the rear wheels Il, these suspension units all having a common pivotal connection with the main transverse shaft 5. Each of such suspension units embodies a substantial lever arm member which is provided in the manner of a lattice girder, or the like, including spaced bearing necks which are pivotally connected with said main shaft 5 as at 2l to mount the front wheel suspension units 6, 1, and as at 28 to mount the rear wheel suspension units 8, 9. Each suspension unit embodies an individual shock absorbing means 29 comprising a spring mounted take-up rod attached to the associated wheel mounting and pivotally connected to the auxiliary transverse shaft 23 or 24 nearest thereto.

Figs. 1 and 2 illustrate in detail the improved form of differential gearing of the invention which is admirably suited for use with the chassis construction just described wherein the gearing is housed within the casing II, Figs. 1 and 3, in operative relation to the transmission T. Said casing II preferably is disposed slightly rearwardly of the horizontal main shaft 5 and is supported by any suitable means such as sleeve I attached to said transverse shaft 5 between the opposed inner bearing necks 28 of lever arms 8, 9. Inasmuch as the differential is located adjacent the transmission, the same may be of the type involving a simplified, inexpensive construction which is built in with the transmission in said casing II together with a suitable partition to H divide the volume of grease.

As shown in Fig. 1, at a suitable point from the end of the power or transmission main shaft 30, a substantial spider wheel 3|, or the like, is fastened thereto by key 32, and, referring to Fig. 2, the said spider wheel 3l is seen provided preferably in the manner of a disc-like member formed with opposing radial recesses 33 in which pintles or arms 34 are suitably disposed. These arms 34 carry the primary spider gears or differential pinions 35 held in assembled relation therewith by plates 35 which are apertured to receive said arms and otherwise bolted to the periphery of the spider wheel 3l on either side of said radial recesses 33. Nut-s 31 threaded onto projecting end portions of said arms 34, limit the outward thrust of the differential pinions lor spider gears 35 in operation.

On either side of said primary spider gears 35, there are meshed therewith differential side gears 38, 39, rotatably mounted on the shaft 30, and provided with sleeve extensions 40, 4I, respectively. A bearing 42 supported by the bearing seat 43 in the casing is fitted onto the sleeve 40 and retained in position against the rear face of spider gear 33 by a suitable bearing cap member bolted to said bearing seat 43. A drive gear 44 is fixed to said sleeve 40 by a key 45, while a lock nut 45, threaded onto the extremity of said sleeve 40, holds the several elements in the assembled relation shown.

In a similar manner, a bearing 4'I is fitted onto `sleeve 4I against the rear vface of differential side gear 39, said bearing being supported in the casing by a substantial arm-type bearing seat 48 and bearing cap therefor disposed wholly to one side of the power or transmission shaft 33. A drive gear 49 is keyed to the sleeve 4I of side gear 39 and these elements like- Wise are held in assembled relation by a lock nut 50 threaded onto the extremity of said sleeve 4I adjacent the endl of said power shaft.

Said drive gear 49 is meshed with an internal gear I iixedly secured to the stub shaft I2 which is supported in the casing II as by bearing 52 and associated bearing seat. Said stub shaft I2 extends toward the associated rear wheel drive shaft I5, Fig. 3, and is connected thereto by universal coupling I4. Likewise, stub shaft I3 is connected by universal coupling I4 to the other rear wheel drive shaft YI5. The stub shaft I3 is suitably mounted in the casing as by the bearing 53, Fig. l, and associated bearing seat and is adapted to be rotated in an opposite direction to that of stub shaft I2 by means of gear 54keyed vthereto and driven by drive gear 44 on sleeve 40, as aforesaid.

In operation, when power from the motor rotates the transmission shaft 30 and the spider wheel 3I carried thereby, the differential pinions or primary spider gears 35 on said spider wheel 3| move therewith to rotate the differential side gears 38, 39, which, through sleeves 43, 4I thereon, respectively, rotate in the same direction the drive gears 44, 43, keyed lto said sleeves 40, 4I, respectively. Stub shaft I3, of course, is rotated in an opposite direction to drive gear 44 which drives gear 54 fixed to said stub shaft I3. However, internal gear 5I turns in the same direction as drive gear 43, and accordingly, stub shaft I2 fxedly connected to said internal gear 5I, rotates therewith in a direction opposite to that of stub shaft I3, as indicated by the arrows,

Awhereupon the differential gearing rotates the wheel driving shafts I5, I5', Fig. 3, in opposite directions from said stub shafts I2, I3, respectively, through the universal couplings I4, I4', respectively.

From the foregoing, it will be understood that the dierential gearing of the present invention is particularly advantageous at high speeds in that the torque of one wheel driving shaft equalizes that of the other and accordingly, there is eliminated a primary cause for objectionable swaying of a car body which often takes place in vehicles having only a single drive shaft due to the unbalanced torque of such single drive shaft at high speeds.

Although the wheel driving shafts I5, I5' are shown in Fig. 3 as extending to and driving the rear wheels I'I of a vehicle having 'a forwardly mounted motor, the differential gearing mechanism of the present invention is readily adapted for operation and use with equal effectiveness in the event a rearwardly mounted motor is employed. In a similar relation, the differential gearing may be so mounted as to provide a front wheel drive whereupon power from the differential stub shafts I2, I3, would rotate the wheel driving shafts I5, I5', as connected with suitable driving mechanism associated with the front wheels I8, as may be readily understood.

In the differential gearing of the present invention, an important advantage resides in the relatively simple, compact and reliable construction thereof including the location thereof on the transmission main shaft and near the motor such that the transmission of power is effected with a minimum of loss. In addition, the power to the wheel driving shafts is transmitted directly from the differential gearing so mounted on the transmission main shaft to provide, in this respect, a further simplied construction in which there is a considerable saving in wear and loss of power in the operating parts.

A further advantage resides in the fact that the differential gearing of the present invention permits of a desirable reduced speed of the wheel driving shafts which is considerably less than that of drive shaft arrangements heretofore employed, while also rotating such wheel driving shafts in opposite directions in a manner whereby the torque thereof is balanced, this being particularly desirable in a vehicle moving Aat high speed inasmuch as objectionable body sway is thereby minimized and practically eliminated.

While the invention has been described indetail with a specific example, such example is intended as an illustration only, since it will be apparent 'to those skilled in the art that other modications in the construction, arrangement and general combination of parts thereof may be devised Without departing from the spirit and scope of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, with all changes falling Within the scope, meaning and range of equivalency of the claims intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In an automotive vehicle including a transmission having a main shaft extending therefrom, a diierential gearing associated with said main shaft and directly connected to a pair of angularly disposed shafts leading to the vehicle drive Wheels, said differential comprising a spider wheel having radial arms and keyed to said main shaft, differential pinions carried by said radial arms of the spider wheel, means for retaining said pinions on said arms of the spider wheel, a diierential side gear at each side of the spider wheel and meshed with said pinions of the spider wheel, sleeves associated with said side gears, bevel drive gears secured to said sleeves, and driven gears meshed with said bevel drive gears and fixed onto said angularly disposed shafts leading to the vehicle drive wheels, one of said driven gears being an internal gear, whereby said shafts are rotated in opposite directions in the operation of the differential.

V `2. In an automotive vehicle including a transmission having a main shaft extending therefrom,

a `differential gearing associated with said main shaft and directly connected to a pair of angularly disposed shafts leading to the vehicle drive wheels, said differential comprising a spider wheel having radial arms and keyed to said main shaft, differential pinions carried by said radial arms of the spider Wheel, means for retaining said pinions on said arms of the spider wheel, a differential side gear on said main shaft at each side of the spider wheel and meshed with said pinions of the spider Wheel, sleeves associated with said side gears and extending in opposite directions on saidl main shaft, bearings on said sleeves, bevel drive gears secured to said sleeves n adjacent said bearings, and driven gears meshed 

